Cockroaches, long feared for their ability to invade our homes and kitchens, are more than just an unpleasant sight; they can also be serious threats to our health.

As one of the most resilient creatures on the planet, cockroaches have developed an uncanny ability to survive in various environments.

They are also vectors (carriers) of a wide variety of harmful microorganisms, including bacteria, viruses and parasites, that can negatively impact human health.

Research has shown that cockroaches can carry over 30 different types of bacteria, many of which are harmful to humans.

For instance, Salmonella species, Escherichia coli and Staphylococcus aureus are common bacteria found on cockroaches that can cause food poisoning, gastrointestinal illnesses and other diseases.

Cockroaches are often found in unsanitary environments, where they pick up bacteria from decaying food, trash and sewage.

These bacteria are then spread to various surfaces, including countertops, kitchenware and food.

Once transferred, these bacteria can thrive and multiply, especially if proper hygiene practices are not consistently followed.

This can result in foodborne illnesses when contaminated food is consumed.

In a study published in the journal Parasitology Research last year (2024), cockroaches were found to carry parasites that cause serious intestinal infections.

Entamoeba histolytica, a parasite responsible for amoebic dysentery, and Giardia lamblia, known for causing giardiasis, are just two of the many parasitic organisms that cockroaches can harbour.

By coming into contact with contaminated waste, cockroaches can spread these parasites from one place to another, creating a chain reaction of contamination.

Allergies and asthma

While most of us think of foodborne illnesses when it comes to cockroaches, there’s another significant health concern: allergies and asthma.

Cockroaches are a major cause of allergic reactions, particularly in urban settings.

Their saliva, faeces, and even their body parts, contain potent allergens that can trigger severe allergic responses in sensitive individuals.

In fact, these allergens are one of the leading causes of asthma attacks, particularly in children.

According to a 2023 report in the Journal of Allergy and Clinical Immunology, cockroach allergens are widely recognised as one of the most common indoor allergens.

These allergens can become airborne and be inhaled, causing symptoms such as sneezing, wheezing, coughing and shortness of breath.

For people with asthma or other respiratory conditions, exposure to cockroaches can lead to more frequent and severe attacks, potentially leading to hospital visits or medication use.

When eating out

The presence of cockroaches in restaurants or food establishments is more than just an inconvenience; it can signal serious hygiene issues.

Cockroaches can slip in through the tiniest of cracks to infest a building.

Cockroaches are opportunistic creatures that thrive in places with easy access to food and waste.

Therefore, when you see cockroaches in a dining area, it is often a sign that the establishment is not up to standard in terms of cleanliness and sanitation.

Cockroaches, while searching for food, can leave a trail of bacteria and parasites in their wake, contaminating anything they come in contact with, including food, utensils and surfaces.

Even if the food looks perfectly clean and appetising, the risk of contamination remains high when cockroaches are present.

These pests often crawl over kitchen equipment, counters and food preparation areas, transferring bacteria and pathogens as they go.

What’s more, cockroaches can hide in hard-to-reach areas, making it difficult to completely eradicate them without professional help.

If you encounter cockroaches in a food establishment, it’s a clear indication that proper hygiene protocols are not being followed, and it’s safer to avoid eating there.

To protect yourself, your family and the community, it’s also best to report the infestation to local health authorities and avoid consuming food from establishments with pest problems.

Hygiene rating

In Malaysia, food premises are required to display hygiene certificates with grades such as A, B or C, which indicate their cleanliness and hygiene levels.

These certificates are part of a grading system implemented by local councils to ensure food safety and public health.

The grades, usually printed on brightly coloured certificates, are prominently displayed on the walls of eateries, making it easier for customers to assess the hygiene standard of a restaurant.

However, the design and implementation of these certificates may differ slightly depending on the state and district.

Despite these requirements, many eateries fail to display their hygiene certificates prominently.

This lack of transparency makes it challenging for consumers to make informed decisions.

Instances of missing or hidden certificates often correlate with lower hygiene grades, as some establishments may prefer to avoid highlighting their ratings.

As a consumer, when dining out, we should:

• Look for the hygiene certificate with a clearly displayed grade.
• Enquire with the staff or consider choosing another restaurant if the certificate is missing or not prominently visible.
• Pay attention to the overall cleanliness of the premises, staff hygiene practices and customer reviews.

By selecting eateries that proudly display their hygiene grades, customers can encourage better compliance and higher standards across the food industry.

Be proactive

Ultimately, the health risks associated with cockroaches are substantial and should not be taken lightly.

Whether it’s foodborne illnesses, parasitic infections or respiratory issues, the consequences of cockroach exposure can be severe.

This makes it all the more important to stay vigilant and take action when you see signs of cockroaches in your home or in food establishments.

By staying informed and proactive, we can protect ourselves and our families from the dangers they bring.

Remember to maintain good hygiene both at home and in public places.

Regular cleaning, sealing cracks and being vigilant about food safety can go a long way in preventing cockroach infestations.

If you see cockroaches in your living or dining space, take immediate action to eliminate them and seek professional help if necessary.

Prevention is always better than cure.

By being proactive, we can significantly reduce the risk of exposure to the health dangers cockroaches bring, ensuring a safer environment for everyone.

Dr Vinoth Kumarasamy is a parasitologist and lecturer at Universiti Kebangsaan Malaysia. For more information, email starhealth@thestar.com.my. The information provided is for educational and communication purposes only, and should not be considered as medical advice. The Star does not give any warranty on accuracy, completeness, functionality, usefulness or other assurances as to the content appearing in this article. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.